Ahead of Wednesday’s anniversary, China has gone to great lengths to censor discussion about the tragedy in 1989, when Chinese troops killed unarmed civilians in the center of Beijing. (The exact death toll is in dispute, but some estimate that more than 1,000 pro-democracy protesters were killed.)

In an apparent effort to keep people from recalling the violence, China has taken the drastic measure of blocking access to Google in the country. The country has also taken measures to quell protestors themselves. For example, Chinese authorities arrested a well-known artist named Guo Jian after he created a diorama of Tiananmen Square covered in ground meat.

While Jian’s diorama may have been disturbing, photographs from the actual protest are utterly heartbreaking. We’ve gathered some of more iconic images in recognition of the 25th anniversary.

Adam Taylor and Erin Fuchs contributed to this report.

The protests began in April of 1989, after the death of ousted General Secretary Hu Yaobang.

Chinese police try in vain to contain a huge crowd of student marchers during a pro-reform demonstration in Beijing, China, May 4 1989.

Many saw Hu as a reformer. He had the support of students, who wanted the Chinese government to continue his pro-market and pro-democracy policies.

A truck is almost buried in people as it makes its way through the crowd of thousands gathered in Tiananmen Square for a pro-democracy rally, Wednesday, May 17, 1989, Beijing, China.

Following Hu's official state funeral, some 100,000 students gathered in the Beijing's central square.

Beijing university students wave fists and flags as five Chinese military helicopters buss Tiananmen Square at down Sunday, May 21 1989.

An anti-protest editorial in People's Daily on April 26 enraged the students further.

Unidentified Beijing University students, who have been on a five day hunger strike for democracy, take an early morning break in Tiananmen Square, Thursday, May 18, 1989, Beijing, China.

By May 13, a hunger strike had begun and the crowd had grown to 300,000 people.

Martial Law was declared on May 20.

Beijing University students rally in Tiananmen Square where they have camped for a week to push for political reforms, Saturday, May 20, 1989, Beijing, China.

The People's Liberation Army (China's military) marched on Beijing, only to withdraw a few days later. Protestors would lecture the soldiers, asking them to join their cause.

A Beijing University student reads list of goals in their occupation of Tiananmen Square to Peoples Liberation Army troops, Saturday, May 20, 1989, Beijing, China.

The student protest became split around this time, with no clear leader.

A Chinese military helicopter passes over Tiananmen Square and demonstrating students following the declaration of martial law, Saturday, May 20, 1989, Beijing, China.

But the students and their supporters were clearly occupying Beijing's central square.

Beijing University students listen as a strike spokesman details plans for a rally in Tiananmen Square, which they have occupied for the last two weeks, Sunday, May 28, 1989, Beijing, China.

They even unloaded a 30-foot styrofoam statue, modelled on the Statue of Liberty, in the square.

A statue modelled after the Statiue of Liberty is ready for unveiling in Tiananmen Square, Beijing, China, May 30, 1989.

Protestors mocked government 'bribes' for pro-government marches.

A masked protester from Beijing University leads chants making fun of the government's offer of money and a loaf of bread to people willing to march in a pro-government rally, Friday, June 2, 1989, Beijing, China.

Troops began clearing the square at the start of June.

A student pro-democracy protester flashes victory signs to the crowd as People's Liberation Army troops withdraw on the west side of the Great Hall of the People near Tiananmen Square on Saturday, June 3, 1989 in Beijing.

Protestors resisted.

A young woman is caught between civilians and Chinese soldiers, who were trying to remove her from an assembly near the Great Hall of the People in Beijing, June 3, 1989.

Most were unarmed but some had rocks and other weapons.

Civilians hold rocks as they stand on a government armoured vehicle near Chang'an Boulevard in Beijing, early June 4, 1989.

Violence erupted.

A student protester puts barricades in the path of an already burning armoured personnel carrier that rammed through student lines during an army attack on anti-government demonstrators in Beijing's Tiananmen Square, early June 4, 1989. A govenment soldier who escaped the armoured vehicle was killed by demonstrators. Pro-democracy protesters occupied the square for seven weeks; hundreds died in the early hours of June 4, 1989 when troops shot their way through Beijing's streets to retake the square.

Officially, 241 people died.

The bodies of dead civilians lie among mangled bicycles near Beijing's Tiananmen Square in this June 4, 1989 file photo.

Other numbers, ranging into the thousands, have circulated, with none confirmed. Many of the deaths happened outside the square, with soldiers firing directly at unarmed protesters.

A ceremony of PIA troops march down Chanan Blvd. firing indiscriminately to clear the street of citizens as the army faction occupying the center of Beijing prepares for the rumoured arrival of opposition troops converging on the city, June 5, 1989, Beijing, China.

Many more were injured.

A blood-covered protester holds a Chinese soldier's helmet following violent clashes with military forces during the 1989 pro-democracy demonstrations in Beijing's Tiananmen Square in this June 4, 1989 file photo.

The iconic footage of a man standing up to a PLA tank occurred the next day.

A Chinese man stands alone to block a line of tanks heading east on Beijing's Cangan Blvd. in Tiananmen Square on June 5, 1989. The man, calling for an end to the recent violence and bloodshed against pro-democracy demonstrators, was pulled away by bystanders, and the tanks continued on their way. The Chinese government crushed a student-led demonstration for democratic reform and against government corruption, killing hundreds, or perhaps thousands of demonstrators in the strongest anti-government protest since the 1949 revolution. Ironically, the name Tiananmen means 'Gate of Heavenly Peace'. (AP Photo/Jeff Widener)

Tens of thousands of people were arrested after the protests, and an unknown number were likely executed.

Crowds of curious Beijing residents gather to look at the military hardware in Tiananmen Square Wednesday, June 7, 1989 in Beijing. (AP Photo/Sadayuki Mikami)

Officially China still tries to ignore the legacy of the event, with searches on the popular Chinese microblogging site Weibo banned today.

Other Chinese people remember the massacre as it was filtered through the country's state-run TV stations.

Bicyclists peddle through the ruins of the last weeks battle between the Peoples Liberation Army and students demonstrating for democracy in Tiananmen Square, June 10, 1989, Beijing, China. This scene is located some three miles from the square. (AP Photo/Jeff Widener)

The novelist Murong Xuecun recently wrote that China's president President Xi Jinping may be more paranoid than those who came before him.

Despite the paranoia on mainland China, there are still relatively robust protests in Hong Kong. 'We will never forget the Tiananmen massacre, because until now there's been no justice,' one woman reportedly said while marching through Hong Kong.

Protesters wearing headbands with a slogan reading 'Denounce butcher regime' attend a candlelight vigil outside the Chinese liaison office in Hong Kong Tuesday, June 3, 2014, to mark the 25th anniversary of China's crackdown on pro-democracy protests on Tiananmen Square on June 4.